AiiDAlab – an ecosystem for developing, executing, and sharing scientific workflows

We present our latest results on linking the process–structure–properties–performance (PSPP) chain for metal additive manufacturing (AM), using a multi-scale and multi-physics integrated computational materials engineering (ICME) approach. The abundance of design parameters and the complex relationship between those and the performance of AM parts have so far impeded the widespread adoption of metal AM technologies for structurally critical load-bearing components. To unfold the full potential of metal AM, establishing a full quantitative PSPP linkage is essential. It will not only help in understanding the underlying physics but will also serve as a powerful and effective tool for optimal computational design. In this work, we illustrate an example of ICME-based PSPP linkage in metal AM, along with a hybrid physics-based data-driven strategy for its application in the optimal design of a component. Finally, we discuss our outlook for the improvement of each part in the computational linking of the PSPP chain.

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Optimal Design for Metal Additive Manufacturing: An Integrated Computational Materials Engineering (ICME) Approach

The present article describes design, architecture, and implementation of the Aachen (“Aix”) Virtual Platform for Materials Processing—AixViPMaP®. This simulation platform focuses on enabling automatic simulation workflows in the area of microstructure evolution and microstructure property relationships by continuum models. Following a description of a variety AixViPMaP® functionalities like user management, the currently implemented software tools, simulation workflows, data storage, grid infrastructure, and many more, some example workflows which have been run on AixViPMaP® are presented in detail. These workflow examples—although each being specific—can readily be transferred to other materials or to similar processes as the major simulation tools used in these workflows are all generic and thus applicable to a wide range of metals and technical alloys. The article concludes with a discussion on the performance and benefits of the platform, an outlook on its future development and on its open, future availability for both academic and commercial use.

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AixViPMaP ® —an Operational Platform for Microstructure Modeling Workflows

This paper discusses the compression of round magnet wires. The feasibility of forming operations within grooves of electrical machines after the winding process is investigated using a scientific methodology. This approach is motivated with the need for higher fill factors, comparable to the ones of hairpin technology. By using individual parallel conductors with higher number of turns, however, it is also possible to reduce frequency-dependent losses in higher drive speed ranges. In addition, the insulation layer quality for round wires is superior to the ones of profile wire due to the coating process, with the exception of extrusion insulations. This results in a better applicability of round wires for compression and higher voltage applications as well. At first, current state of technology is presented and applicable winding test procedures as well as a test setup is introduced. For experimental validation a model groove was designed and built. Possible groove design parameters are introduced and chosen according to a Design of Experiment approach (DoE). Different metrology approaches for the characterization of the insulation quality after processing and the resulting wire deformations are discussed. Significant input variables are pressing force, wire insulation thickness (measured in grades), number of turns per coil as well as wire diameter. Key output variables are the achieved fill factor improvement, the partial discharge voltage and the electrical resistance of the coil. The experimental plan, according to a full- factorial DoE, the chosen methodology and concluding results are being discussed based on main effect diagrams. In the outlook, the further investigation topics are outlined. It can be shown that the compression process of enameled round copper wires is well suited, up to a quality critical limit, for the production improvement of coils in grooves of electrical machines. The process therefore represents a promising approach to increase the fill factor, taking into account the electrical insulation properties of the winding. This first investigation can show that some electrical properties, such as partial discharge features, can even be improved in certain areas.

Feasibility Study for Enameled Round Copper Wire Compression within Slots of Electrical Machines

Finite element analysis of extrusion process using aluminum alloy

Development of levelling strategies for heavy plates via controlled FE models

Iron loss and limited magnetic flux density are constraints for NGO electrical steel used in highly efficient electrical machinery cores. The most important factors that affect these properties are the final microstructure and the texture of the NGO steel. Reviewing the whole process chain, cold rolling plays an important role because the recrystallization and grain growth during the final heat treatment can be strongly affected by the stored energy and microstructure of cold rolling, and some texture characteristics can be inherited as well. Therefore, texture evolution during cold rolling of NGO steel is worth a detailed investigation. In this paper, texture evolution in cold rolling of non-oriented (NGO) electrical steel is simulated with a crystal plasticity finite element method (CPFEM) model. In previous work, a CPFEM model has been implemented for simulating the texture evolution with periodic boundary conditions and a phenomenological constitutive law. In a first step the microstructure in the core of the workpiece was investigated and mapped to a representative volume element to predict the texture evolution. In this work an improved version of the CPFEM model is described that better reflects the texture evolution in cold rolling of NGO electrical steel containing 2.4 wt.-% Si. This is achieved by applying the deformation gradient and calibrating the flow curve within the CPFEM model. Moreover, the evolution of dislocation density is calculated and visualized in this model. An in depth comparison of the numerical and experimental results reveals, that the improved CPFEM model is able to represent the important characteristics of texture evolution in the core of the workpiece during cold rolling with high precision.

Stephan Hojda

Papers

AixViPMaP ® —an Operational Platform for Microstructure Modeling Workflows

Development of levelling strategies for heavy plates via controlled FE models

Model for texture evolution in cold rolling of 2.4 wt.-% Si non-oriented electrical steel

Damage dependent material properties in a Finite Element Simulation of a hybrid forward extrusion process

Umformtechnik für die Elektromobilität